Concrete pipe manufacturing machine



Nov. 1,2, 1940. A.o'RAH1| Y CONCRETE PIPE MANUFACTURING MACHINE HHHHHHH ad Filed Feb. 3, 1939 nventqr am a @M godly Gttomeg Patented Nov. l2, 1940 AodhganfORahilly, Mooreen, Cloniilalkin,Ireland Application February s, lass-.Senn No. 2,541,401

o In Ireland July 5, 1938 l 4 Claims.

factured by what is known as the packer` headv process in whichA a semi-dry mix of concrete is delivered into a` vertical mold and is there compressed by packing wings` against 'the interior y wall ofthe mold soas to form the wall of the pipe. Whenpipes thus manufactured are sub- `jected to the usual hydrostatic tests there is found to be a tendency for the test water to sweat through the wall of the pipe. o

By substituting 'a mix that is substantially wetter for the semi-dry mix ordinarily employed,

the aforementioned sweating., Itendency can be lessened or even entirely obvia-ted if the substif tuted mix is sufficiently wet. The employment of such a wet mix gives rise however to the serious manufactuiingdisadvantaige that the mold cannot be stripped for a considerable time after the construction of the pipe owing to the inability of the latter to retain its formationwhilst in the semi-plastic condition due to the `superadded water.

To meet these objections it has already been proposed in the manufacture of concrete pipes by the aforementioned packer head process t0 lead water or other liquid down through the central revolving shaft ofthe pipe making machine and to radially project it from a single discharge nozzle in the said shaft on to the portion of the concretemidway between two of the packer wings that is about to be formed into the `inner wall of the, pipe.

It has been found in 'practice that this method of applying the extra liquid did not produce satisfactory results. received an excess of superadded liquid so that it was unable to retain its molded form in the pipe wall while the remaining portions of the concrete received no superadded liquid. The resulting pipe showed a series of wet bands alternating with a series of dry bands throughout the length of the pipe.

According to the present invention an appropriate quantity of Water or other liquid is fed from the central shaft or from a pipe attached Some portions of the concrete thereto to a nozzle carried on the operating face of each packing "wing whenceit is discharged obliquely into -thatportion of the semi-dry mix in the mold thatison the point of being formed intothepipe wall, in such a manner and to such l an extent Ythat the inner periphery and part `of the pipe wall adjacent thereto will be composed of concrete with the superadded watergwhilst the outer periphery and' part of the pipe wall adjacent thereto willbe composed of the semidry mix concrete. This arrangement ensures that the superadded water or other liquidis even-v ly distributedover the entire mass of the concrete forming the inner wall of the pipe.

The' invention will now be `described having reference to the accompanying drawing in which:

Fig. 1 shows in elevation portion of the central shaft of the packer head machine to which is connected the member known as the packer head fitted with the water distributing apparatus, the Whole 4being situated within portion of a pipe shown in cross section; l Y l i Fig. 2 is a cross; section along` line A`A in Figi. o

Fig.3 is a section of the trowelling member.

Fig. 4` shows the water distributing apparatus disconnected from the known parts of the machine to which itis applied.

The samel reference numerals refer to the same parts throughout. y Referring tothe ijayvilfig2 numeral I is the Vertical revolving shaft of the machine, to the lower endoof which is connected the known form tioned. l The object of this trowelling member is to smooth 01T imperfections that may show them# selves on the inner periphery of the pipe lwall during the courseof construction. The Wall of the concrete pipe in the course of manufacture within the mold Bis indicated by numeral 6.`

A central passage? having a suitable connecf tion With a water` supply extends downwards from the upper end of the verticalfsh'aft i to apoint substantially 'central with 4the center blockvtS, from which` point passages 9,9,"Fig. 2 lead to that outer surface of the wings 4,4, which comes into l operative contact with the semi-dryconcrete mix to be compressed. Connections l0,lll are progoor..

' convenient distance above the-center blockl 3 instead of being brought through the block itself.

In -this case, to avoid weakening the vertical shaft one of the passage 9 may be omitted, and one con'- nection IIJ is fitted to the outlet of the remaining passage 9 and adapted to take both the tubes II.

In order to diminish risk of damage the tubes Il are caused to lie as closely as possible against the operative faces of the wings 4,4. -The nozzles I2 are so positioned that water discharged therefrom will impinge on and consequently further moisten that portion of the semi-dry concrete mix (shown by numeral I3 in Fig. 2) that is about to be compressed to form the portion of the wall adjacent to the inner periphery of the pipe.

Fig. 3 illustrates in cross sec-tion the trowelling member 5 aforementioned. The said member is supported on an extension I4 of the vertical shaft Ifand is of piston-like form of appropriate depth and of diameter substantially thatof the bore of the pipe being manufactured. The periphery I5 is very slightly tapered, the diameter of the upper rface being somewhat less than that of the lower face, the object being that as the member rises with thepacker head during operation, its application against the inner wall `of the pipe Ywill be gradual and any dragging ofthe finished surface avoided.

The said trowelling member is freely supported on'the shaft extension I4 on ball or roller bearings I and I'I of any known make, the hub I8 being enlarged for housing them; the member 5 can thus revolve independently of the main vertical shaft I.

It is to. be understood that the aforementioned construction Vfor the support of the trowelling member is given by way of illustration of one form only; any other known suitable support or connection with the shaft IA may be arranged, the essential point being that thel said member is supported that in opera-tion it does not revolve l with the central vertical shaft but rises with it smoothly off the interior of the pipe wall.

In operation the semi-dry mix of concrete is fed into the machine in the usual way and falls on the upper face of the long bottom 'L` Asy the semi-dry mix is compressed outwards against the pipe mold by the packing wings 4,4, water under pressure is directed thro-ugh the passage 'I' in the vertical shaft I, passes through the openings 9,9 and is sprayed through the nozzles I2, I2' obliquely on to that portion of the mix which will form thek inner peripheryV of the pipe wall, which is thus formed of a wetter and denser concrete. The quantity of water can be regulated by any known customary means and is varied according to the thickness of the wall of the pipe under construction in such a manner that the water from the nozzles I2 hasnot time to penetrate the entire mass'of concrete; consequently that portion of the mix which will form the outer periphery and that part of the pipe wall adjacent thereto remains in its original semi-dryrcondition. `By adjusting the superadded water can be varied.

It is tobe understood that the drawing illustrates only one embodiment of the inventon and that changes in construction may be effected without departing from the spirit thereof. For example in the center block 3 only one water outlet 9 may be arranged and fitted with any suitable known type of connection to take the requisite number of tubes I I leading to the spraying nozzles I2. Further instead of directing the water through a central hole in the vertical shaft, it may be conveniently led through a pipe exteriorly with the outlet nozzles aforementioned.

I claim: Y

l. A concrete pipe manufacturing machine comprising a central shaft vertically movable and rotatably mounted within a mold, carrying a packer head and a center block with packing wings secured thereon, piping on the head in communication with a source of water supply, a nozzle connected to the piping and carried on the operating face of two or more packing wings, said nozzle being so relatively arranged with respect to said packing Wings and the interior portion of the pipe being formed as to cause the water issuing from said nozzle to impinge obliquely in that portion of the concrete mix about to be formed into the inner periphery of the pipe Welland part adjacent thereto.

packer head and a center block with packing wings secured thereon, said shaft being hollow and vin communication with a source of water supply, said shaft also having an orifice in communication with its hollow portion, said center block having passages communicating with said orifice, piping connecting with said passages and carried by said head, and a nozzle directed and carried on the operating face of each packing wing so as to impinge obliquely on that portion of the concrete mix about to be formed into the inner periphery of the pipe wall and part adjacent thereto.

3. A concerete pipe manufacturing machine machine comprising a central hollow shaft in communication with a source of water supply andv vertically movable and rotatably mounted within aY mold, carrying a packer head and a center block with packing wings secured thereon. said shaft having an orifice, a nozzle carried by said. head, connections between said orifice and said nozzle, said nozzle carried on the leading face of a packing wing and positioned and arranged relatively to said wing and the internal surface of the pipe being formed in a manner causing the water issuing from the nozzle to impinge obliquely on that portion of the concrete mix about to be formed into the inner periphery of the pipe wall and part adjacent thereto.

4. A concrete pipe manufacturing machine as claimed in claim 1 characterised in that a cylindrical troweling member is supported on the central Vertical shaft below the long bottom so that the said troweling member does not revolve with the kcentral vertical shaft, and smooths off the interior surface of the pipe wall.

AODHGAN ORAHILLY.

` attached to thg said shaft and suitably connected 

